Forklift trucks having raisable forks are often employed to lift and move articles too heavy or otherwise unsuitable for manual handling. Such vehicles have lift masts mounted for lifting the load so that the load may be transported to another location and deposited. The lift masts typically have a carriage which is mounted on uprights of the lift mast and selectively positionable at a desired height. Usually, a pair of spaced apart forks are mounted on the carriage and are positioned beneath the load for lifting it.
In situations where the load to be lifted is relatively tall or tall and top-heavy, the potential for inadvertent tipping under the dynamics of vehicle operation exists. Loads which are relatively light in weight also tend to have a higher incidence of inadvertent movement on the forks caused by the vehicle dynamics. In order to prevent potentially very expensive damage to loads caused by tipping over during movement by forklift trucks, such movement must often be carried out at a much slower rate than would otherwise be necessary. However, such slower movement decreases the handling productivity of such loads which, consequently, increases the cost of labor in handling such articles.
In order to avoid the expense of repair or replacement of articles damaged during handling by forklift trucks and to increase the handling productivity of such articles, various types of load stabilizers have been devised for forklift trucks. Many of the load stabilizers are side clamping type devices including a pair of side clamps to engage the lateral sides of the article to be carried or top clamping devices which engage the tops of the articles. The clamping types of load stabilizers often require complex forms of attachment to the existing lift carriage and the connection of operating cylinders and controls to the existing hydraulic systems of the lift trucks on which they are mounted.
Because of the complexity of installation of such stabilizers on fork lift trucks, frequent mounting and removing is not convenient. Such stabilizers may interfere with the use of a forklift truck for general purpose article handling. Because of these factors and, additionally, the expense of such clamping types of load stabilizers, they are often only justifiable economically when there is a high volume of articles requiring special handling. Finally, clamping type load stabilizers are not appropriate for some types of articles and may, in fact, be damaging thereto.
The handling of tall and top-heavy articles would benefit from a load stabilizer apparatus which is relatively simple and inexpensive in construction, which is simple to install on a conventional type of forklift truck with minimal modification thereto, and which is simple to deploy and stow.